OT: "- we do not understand all the processes (including feed back loops) that lead to temperature change;
We do not understand all the processes within the human body.
"- without that understanding, we cannot create models/simulations that can meaningfully predict the future;"
Without that understanding we can not model/predict how individuals will react.
"- that we do not really know whether warmer is better or worse (Plimer supports warmer);"
We do not even know what ideal health states are.
"- that it is folly with such limitations and at enormous cost to attempt to change the course of the earths temperature. "
Thus it is folly to attempt with such limitations and great cost to improve change the human condition.
-------
Just a few points other points.
. It's not a matter of warmer vs cooler, but the rate of change that is the key issue.
. That climate varied in the past and was not driven by CO2 is a complete straw argument. Nobody denies this.
. The first order effects of human induced CO2 are fairly clear. True they are only something like 30%(?) of the total effect prediccted in present models (the rest being mainly due to the temp driven water vapour positive feedback), but is fairly hard to deny.
And on a practical point. Why is reducing our fossil fuel needs such a costly bad idea? Nukes, efficiency, alt energy are all pluses on both CO2 and the US economy.